1. Field of the Invention
The present invention relates to a semiconductor manufacturing process, more particularly, the present invention relates to a voltage stepping down device manufacturing process.
2. Description of Related Art
In traditional arts, stepping down a higher voltage potential to a lower voltage potential is well known to the industrial fields. Voltage stepping down devices, such as voltage dividers and transformers, are widely used to supply a predetermined voltage potential to electronic systems. A transformer includes plural coupled coils having proportional turn numbers to each other for achieving voltage stepping down. However, transformers are generally huge in size and cannot be easily integrated within semiconductor devices. Therefore, higher manufacturing cost and huge space occupation are their inevitable disadvantages.
Voltage dividers formed with resistors generally suffer from resistance variation problems. Temperature dependence of resistors lowers the precision of the voltage potential supplied by voltage dividers. Moreover, the power consumption caused by resistors is another issue to be concerned. In general-purpose applications, when a constant voltage source is needed in an electronic circuit, a device capable of supplying stable voltage potential with lesser die space occupation and lower power consumption is especially desired by the industrial filed.